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<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      .box {
        width: 400px;
        background: #f00;
        /* overflow: hidden; */
      }
      .son {
        float: left;
        zoom:1;
      }
      .son ::after {
        display: block;
   clear: both;
   content: "";
   height: 0;
   visibility: hidden;
      }
    </style>
  </head>

  <body>
    <div class="box">
      <div class="son">我是浮动的子元素fdddddddds
          <p>22334</p>
      </div>
    </div>
  </body>
</html>
